Desktop antimatter gun exists and could shed light on black holes

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Though “gun” might call to mind images of rifles and bullets, in a very real way researchers at the University of Michigan have created a meter-long device capable of shooting a stream of anti-electrons, in other words–an antimatter gun. Additionally, unlike prior models, this one doesn’t require several kilometers of free space and a multi-national effort. It can sit on a lab bench with only a cutting-edge laser as its bottleneck.

It works by using a petawatt laser called the Hercules laser (seen above) to blast a sample of inert helium gas and produce as a result a stream of electrons. Letting this relativistic-speed beam of electrons, smash into an atomically thin sample of gold foil produces two beams as a result, one of electrons and the other of positrons. Since they have an opposite charge, they are easy to separate with a magnet, and each beam is safely stopped by an absorber like teflon. Though the beam lasts for only femtoseconds, it produces a density of positrons only previously found from large-scale colliders like those found at CERN.

The ability to create positrons without the need for LHC-like colliders is obviously exciting to physicists, but it could be immediately applied to astrophysicists for studying so-called “leptonic jets.” These are forms of the relativistic jets of matter that are thrown out by all quickly rotating massive objects, such as quasars, but which are only associated with black holes and eject only leptons like electrons and positrons. By studying the behavior of generated positrons, they could walk back to the origin, composition, and behavior of such jets.

The idea of an antimatter gun is, ironically, an old one. After all, the name of the reaction that occurs when matter and antimatter meet is annihilation; weaponization is not an enormous logical leap. Shooting gobs of antimatter will likely not be easily possible on Earth, since the air would confound any such attempt. In space, however, a coherent beam or discreet package of antimatter could travel through the vacuum while losing relatively little to annihilation — until they hit their target, of course.